Regeneron Halts Enrollment of Critically Ill Patients in COVID-19 Antibody TrialRegeneron Pharmaceuticals has decided to halt enrollment of very sick patients with COVID-19 in its trial studying antibody cocktail REGN-COV2... The decision to halt critically ill patients was made in response to Regeneron’s independent safety board finding a potential safety signal and an unfavorable risk-benefit profile of the monoclonal antibody therapy in a subgroup of patients requiring high-flow oxygen or mechanical ventilation. These patients are generally sicker and hospitalized because they are in the advanced stages of the disease. The Tarrytown, N.Y.-based pharmaceutical company says it is blinded to the...